On Wednesday, Arizona took an hour and 58 minutes to execute Joseph Wood, a convicted murderer. Injected with a lethal mix of sedatives and painkillers, Wood was seen to be “gasping and snorting” for more than an hour and was confirmed to be still alive after 70 minutes. One eyewitness counted 660 gasps. Another said Wood was “like a fish on shore gulping for air”. Wood’s death took so long that his lawyers had time to file an emergency appeal while the procedure was taking place.

The eighth amendment to the US constitution outlaws the use of cruel and unusual punishment, but the US supreme court has ruled that the death penalty does not violate that ban. Many would disagree. Penal Reform International classes the death penalty as the ultimate cruel, inhuman and degrading punishment and more than two-thirds of the world’s nations have now abolished it either in law or in practice, as have 18 US states. Whatever one’s opinion in principle about capital punishment, it is hard not to see Wood’s killing as anything other than needlessly cruel and unusual punishment. It was a shameful act for a civilised country.

Yet it was not exceptional. The Wood execution has many echoes of the botched execution by injection of Clayton Lockett in Oklahoma in April. Similar distress marked the execution of Dennis McGuire in Ohio in January. There have been several other cases – including of botched electrocutions and asphyxiations – since the US restarted executions in 1977.

Amnesty International classes the United States as one of the world’s nine “persistent executioner” states – those which have executed criminals in each of the past five years. The others are Bangladesh, China (which is estimated to execute more prisoners than the whole of the rest of the world put together – all in secret, unlike those in the US), Iran, Iraq, North Korea, Saudi Arabia, Sudan and Yemen. Executions in the US have fallen by half in the past 15 years and the US kills far fewer prisoners than China, Iran and Iraq in particular. But this is not a club to which America should be comfortable belonging. It does massive international damage to the US’s reputation.

Capital punishment remains destructively entangled in America’s culture wars. If it is to continue, the US will have to devise a swifter form of licensed execution. The current shambles, much of it the result of desperation in the face of welcome global campaigns against the suppliers of lethal drugs, has created an intolerable situation for prisoners and the nation alike. Until it is fixed, US states should suspend the death penalty. What the US really needs, though, is to find dignified ways to face up to, as a nation, the failure and damage that are associated with a punishment that is now so clearly, in and of itself, both cruel and unusual.